High Precision
Our power converter uses advanced algorithms to provide accurate conversions with up to 10 decimal places precision for professional engineering calculations.
Mobile Optimized
Fully responsive design that works seamlessly on all devices. Convert power units on-the-go with our mobile-friendly interface.
Multiple Units
Support for 8 different power units including watts, kilowatts, horsepower, BTU/hr, and more. Perfect for electrical and mechanical engineering.
Frequently Asked Questions
What is the difference between mechanical and electrical horsepower?
Mechanical horsepower (hp) equals 745.7 watts and is commonly used in the United States for engines and motors. Metric horsepower (PS) equals 735.5 watts and is used in Europe and other countries. The difference is about 1.4%, so metric horsepower is slightly smaller than mechanical horsepower.
How accurate are the conversions in this tool?
Our power converter uses precise conversion factors and displays results with up to 10 decimal places for maximum accuracy. The conversion factors are based on internationally recognized standards, making them suitable for professional engineering calculations and scientific applications.
When should I use watts vs. kilowatts?
Use watts (W) for smaller power ratings like light bulbs, small electronics, and low-power devices (typically under 1,000W). Use kilowatts (kW) for larger appliances, motors, and electrical systems. For example, a 60W light bulb vs. a 2kW electric heater. Kilowatts are also commonly used for electrical billing and energy consumption measurements.
What is BTU/hr and when is it used?
BTU per hour (British Thermal Unit per hour) is a unit commonly used in heating, ventilation, and air conditioning (HVAC) systems. One BTU/hr equals approximately 0.293 watts. It’s particularly useful for rating the heating or cooling capacity of furnaces, air conditioners, and heat pumps. For example, a 24,000 BTU/hr air conditioner equals about 7 kW of cooling power.
Can I convert negative power values?
Yes, you can enter negative values in the converter. Negative power typically indicates power generation rather than consumption, such as when a motor acts as a generator or when measuring regenerative braking in electric vehicles. The conversion factors remain the same regardless of the sign.
Why do I see different types of horsepower?
There are several types of horsepower due to different historical standards. Mechanical horsepower (745.7W) is used in the US, metric horsepower or PS (735.5W) is used in Europe, and there’s also boiler horsepower, electrical horsepower, and others. Our tool includes the two most common types: mechanical and metric horsepower.
What’s the relationship between power and energy?
Power is the rate at which energy is used or produced, measured in watts. Energy is the total amount of work done, measured in watt-hours (Wh) or kilowatt-hours (kWh). Think of power as the speed at which you use energy. For example, a 100W light bulb running for 10 hours consumes 1 kWh (1,000 Wh) of energy.
How do I choose the right unit for my application?
Choose based on your field and region: Use watts/kilowatts for electrical applications, horsepower for engines and motors (mechanical hp in US, metric hp in Europe), BTU/hr for HVAC systems, and calories/second for thermal calculations in scientific applications. Always check the specifications of your equipment to use the same units.
Can I use this tool for very large or very small power values?
Yes, the tool handles a wide range of values from very small (microwatts) to very large (gigawatts and beyond). For very large numbers, the tool automatically switches to scientific notation (e.g., 1.5e+6) to maintain readability and precision. This makes it suitable for everything from electronic components to power plants.
Is there a difference between electrical and mechanical power?
The units of power (watts) are the same for both electrical and mechanical power, but the context differs. Electrical power is voltage × current, while mechanical power is force × velocity or torque × angular velocity. However, when converting between units like watts and horsepower, the conversion factors apply to both electrical and mechanical power equally.
